Noise damper

ABSTRACT

Noise dampers of sound absorbent material are inserted on the metal grid beams in a suspended ceiling. 
     Hangers, embedded in a structural ceiling, that support the beams, are insulated from the beams by the noise dampers. 
     Sound vibrations generated in the structural ceiling, which is often a floor, are not transmitted through the hangers, to the suspended ceiling, or to the room, below, but are absorbed in the dampers before reaching the grid beams.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to noise control in suspended ceilings. Suchsuspended ceilings have a grid of intersecting metal beams that aresuspended by hangers from a structural ceiling. Panels or drywall sheetsare supported on the grid.

Noise generated in the structural ceiling, which is frequently a floorfor the space above, is transmitted by sound vibrations passing downwardthrough the hangers, which form a sound path, to the grid of thesuspended ceiling. The suspended ceiling, which includes panels ordrywall sheets attached to the beams in the grid, forms a receiver forthe sound vibrations, which broadcasts the resulting unwanted noise tothe space below.

The invention deals with deadening such sound vibrations coming down thehangers.

2. Prior Art

Suspended ceilings are constructed in a special way so that the ceilingsare extremely stable. Over many years, a standard way of constructingsuch ceilings has evolved. Suspended ceilings are constructed at abuilding site by individually explosively embedding an anchor such as aneye bolt, into the structural ceiling, and then attaching a hanger, suchas a wire, to the anchor, by twisting the wire about the anchor. Thelower end of the hanger is attached to a metal beam in a grid thatsupports panels, or drywall sheets, by looping the hanger through a holein the web of the beam and twisting the loop closed around the bulb anda segment of the beam.

The substantial weight of the suspended ceiling is spread among numeroushangers that are spaced every few feet along the main beams in the grid.Each hanger must be individually secured to the structural ceiling, andto the grid beam, by an installer who must keep the grid ofinterconnected main and cross beams level at a desired height. Much timeand effort is required to hang a suspended ceiling grid from astructural ceiling.

Much more time and effort is required where sound attenuator devicesthat dampen the vibrations coming down a hanger sound path, from noisegenerated in a structural ceiling, are used.

In the prior art, to control noise in a suspended ceiling, a noiseattenuator is individually inserted by the installer, about midway inthe length of a wire hanger that is cut into two segments. An uppersegment of the wire hanger is first secured at its top to the structuralceiling, and at its bottom, to a top terminal in the attenuator. A lowersegment of the wire hanger is connected at the top to a bottom terminalin the attenuator, and then, at the bottom of the lower segment, to thegrid beam.

In such prior art attenuator, the upper and lower metal terminals areseparated from each other by a suitable amount of sound vibrationdamping material, such as gum rubber. Sound vibrations coming down thewire hanger sound path from the structural ceiling, which frequentlyserves as a floor for the building level above, are absorbed in thenoise attenuator.

The insertion of such prior art noise attenuators in a wire hanger thatmust be divided into two segments is time and labor consuming, since thenormally single segment of a wire hanger must not only be divided intotwo segments, but each segment must then be secured to the noiseattenuator by passing the hanger through an attenuator terminal, andthen twisting the hanger back around the segment. Thus, instead of justtwo attachments of a single segment of a wire hanger at an upper end tothe structural ceiling, and at its lower end to a grid beam itself, asin prior art suspended ceilings with no noise attenuation, there are twoadditional attachments involving threading the wire hanger through ahole, and then twisting the wire hanger back upon itself, to the noiseattenuator.

Such manual cutting, threading, and twisting must be individually customperformed by the installer of the grid in the field during theconstruction of the ceiling, since good judgment must be exerted at eachwire hanger to keep the grid level, through controlling the length ofthe wire hanger suspensions.

BRIEF SUMMARY OF THE INVENTION

A noise damper, of material that deadens sound vibrations coming down ahanger, is inserted between the grid beam and a hanger in theconstruction of the suspended ceiling.

The noise damper insulates the entire hanger attached to the structuralceiling from contact with the metal grid beam in the suspended ceiling,so the sound vibrations passing down the hanger are deadened in thenoise damper. The noise damper, however, does not interfere with thestructural support of the grid beam and suspended ceiling by thehangers, which are generally of wire, but permissibly of other materialhaving adequate tensile strength to support the suspended ceiling.

The time required to install a suspended ceiling with the presentinvention is virtually the same as the time required to install a priorart suspended ceiling without any noise damping. In the presentinvention, the noise damper, which is of a resilient, sound vibrationdeadening material, can be merely inserted into place, and the hangerattached to the beam by looping a wire hanger through a knock-out in thebeam, as done in the prior art in a suspended ceiling that is not sounddampened.

The knock-out can be shaped so the stress that the suspended ceilingimparts to the hanger where it passes through the knock-out isdistributed over a section of the noise damper, rather than concentratedat the site of the hanger.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a perspective view of the noise damper of the invention.

FIG. 2 is an elevational view comparing

-   -   (a) a prior art suspended ceiling segment without noise damping;    -   (b) a prior art ceiling segment with noise damping; and    -   (c) a suspended ceiling with the noise damper of the invention

FIG. 3 is a side elevational view of a noise damper in place on a gridbeam with a wire hanger looped through the noise damper and beam.

FIG. 4 is an exploded perspective view of a section of a grid beamshowing a knock-out that seats a conforming raised section of a noisedamper.

FIG. 5 is an enlarged sectional view taken on the line 5-5 in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

Although the invention is illustrated with hangers of wires, which isthe predominant material used to suspend present day ceilings, theinvention can be used with other forms of hangers, such as rods, orchains.

In FIG. 2, there is shown comparatively (a) a prior art ceiling withoutnoise damping; (b) a prior art ceiling with noise damping; and (c) thenoise dampened suspended ceiling of the present invention. In a priorart suspended ceiling installation without noise damping, (FIG. 2 a),the suspended ceiling 43, is hung from a structural ceiling 22, by wirehangers 40 embedded in the structural ceiling at the top, and loopedthrough about the grid beam 21 at the bottom. A single length of wirehanger 40 is used.

In FIG. 2 b, a wire hanger is cut in two into segments, 23 and 24, andsecured to the structural ceiling 22 and suspended ceiling 43 as shown.A grid beam 21 is suspended from structural ceiling 22 by an upper wiresegment 23 and a lower wire segment 24, connected to a sound attenuator25. The upper wire segment 23 is looped through an eye bolt 26explosively embedded in the structural ceiling 22, and manually twistedto close the loop 27. Similar connections are made to sound attenuator25 at the bottom of segment 23 and at the top of the lower segment 24.At the bottom of the lower segment 24, there is formed a loop 27 thatpasses through a hole 28 in the web 29 of grid beam 21. The loop 27 isclosed by twisting the wire hanger segment 24.

In the present invention, as shown in FIG. 2 c, a single length of wirehanger 40 is used to suspend a beam 21 at suspension points along thebeam 21. A noise damper is inserted onto grid beam 21 between thesuspension loop 42 at the bottom of wire hanger 40 and the grid beam 21,to insulate the beam 21 from the wire hanger 40. The noise damper 41 ofthe invention deadens the sound vibrations from structural ceiling 22 asthey travel down the wire hanger 40, before the vibrations reach themetal grid beam 21, in the suspended ceiling 43, which would serve as areceiver that would broadcast the noise to the space below.

At the top, the wire hanger 40 is looped through eye bolt 26 explosivelyembedded in structural ceiling 22, and the loop 44 is twisted closed.The lower end of wire hanger is passed through hole 61 in noise damper41 on grid beam 21, and passes through knock-out 46.

Noise damper 41 has an inverted U-shaped upper portion 47 conforming incross section to the bulb 48 of the grid beam 21, as seen particularlyin FIG. 5. A flat lower portion 51 is intended to lie along the web 29of the grid beam 21 as seen in FIG. 5.

A raised insert 53 on flat lower portion 51 is shaped to conform to aknock-out 46, desirably with the shape of an arch 56 at the top. Lipretainers 57 hold the raised insert 53 firmly in the knock-out 46. Anangled lip 58 on the U-shape clip portion 47 retains such U-shapedportion 47 of the noise damper 41 on the bulb 48 of the grid beam 21. Ahole 61 that receives wire hanger 40 extends through the raised insert53 and knock-out 46.

The noise damper 41 is injection molded into one resilient integralpiece from a vibration deadening material. An example of such a materialis thermoplastic vulcanizate, an elastomer, that includes carbon blackand a paraffin wax. Such material, in pellet form, is injection moldedinto the form of the noise damper 41 insert of the invention. The noisedamper 41, when molded, is flexible, and can readily expand when beinginserted onto the grid beam 21, to envelope the grid beam 21 as depictedin the drawings.

The noise damper 41 is inserted onto the beam by passing the invertedU-shape portion 47 vertically downward over the bulb 48 of grid beam 21to seat raised insert 53 in knock-out 46. The noise damper 41 expandswhile being inserted onto the grid beam 21, and contracts to theposition about the beam 21, and into knockout 46, as shown particularlyin FIGS. 3 and 5.

A single length of wire hanger 40, which has been embedded previously inthe structured ceiling, is then looped through the hole 61 in the noisedamper 41, as shown in FIG. 5, and then twisted at 62 to close the loop.

In this manner, the metal wire hanger 40 is insulated from metal gridbeam 21, while still structurally supporting the grid beam 21.

A series of wire hangers 40 and noise dampers 41 are applied at, forinstance, four (4) foot intervals along the main grid beams 21. Theknock-outs 46 may be pre-punched at more frequent intervals, along thebeam, and the noise dampers inserted selectively. The knock-outs 46 donot appreciatively affect the strength of the grid beams 21.

By means of the present invention, as set forth above, the hanger 40which acts as a sound path from the structural ceiling 22 noise sourceto the suspended ceiling 43 which acts as a receiver is interrupted anddampened by the noise damper 41 of the invention.

The noise dampers 41 can be inserted at the job site as the grid beams21 are being hung, or in the alternative, the noise dampers 41 can beinserted on the grid beams 21 before the grid beams 21 themselves areshipped to the job site.

In case of a fire, even though the noise dampers 41 of the invention aredestroyed, wire hangers 40 continue to support the grid beams 21, sincethe wire hangers 40 remain attached to the grid beams 21.

1. In a suspended ceiling having grid beams suspended from a structuralceiling by hangers; the improvement comprising a noise damper ofresilient sound vibration damping material in contact with the grid beamthat insulates a hanger from the grid beam.
 2. The improvement of claim1, wherein the noise damper extends through a knock-out in the web ofthe beam.
 3. The improvement of claim 2 wherein the shape of theknock-out has an arch at the top that distributes force on the beamimparted by a hanger extending through the knock-out.
 4. The suspendedceiling of claim 1 wherein the hanger wires are capable of continuing tosupport the ceiling during a fire.
 5. The suspended ceiling of claim 1wherein the noise damper is in a form capable of being inserted onto agrid beam, and retained on the grid beam by angled lips on the wrap. 6.In a ceiling structure having a. a structural ceiling that is a sourceof noise vibrations; b. hangers that form a noise path for the noisevibrations, and that extend downward from the structural ceiling; and c.a suspended ceiling that includes grid beams, supported by the hangers,that is a receiver for the noise vibrations; the improvement comprisingnoise dampers inserted on the grid beams, that (1) insulate the hangersfrom the grid beams and (2) absorb the noise vibrations coming down thehangers that form the noise path.